#! /usr/bin/racket -f

(define (judge n)
  (cond 
    [(< n 10) 20]
    [(> n 20) 0]
    [else 1]
    )
  )

(define (a n)
   (cond 
     [(< n 10) 10]
     [(> n 20) (* 10 n)]
     [else 1]
     )
  )

(define (interest-rast amount)
   (cond
     [(<= amount 1000) 0.040]
     [(<= amount 5000) 0.045]
     [else 0.050]
     )
  )

(display (judge 5))
(display "\n")
(display (a 5))
(display "\n")
(display (interest-rast 6000))
(display "\n")

